U.S. patent application number 12/456808 was filed with the patent office on 2010-05-13 for fixation system, an intramedullary fixation assembly and method of use.
Invention is credited to Chris Digiovanni, Jamy Gannoe, Jeff Tyber.
Application Number | 20100121324 12/456808 |
Document ID | / |
Family ID | 42165904 |
Filed Date | 2010-05-13 |
United States Patent
Application |
20100121324 |
Kind Code |
A1 |
Tyber; Jeff ; et
al. |
May 13, 2010 |
Fixation system, an intramedullary fixation assembly and method of
use
Abstract
A fixation system, including an intramedullary fixation assembly
and an instrument for coupling the intramedullary fixation assembly
to bones. The intramedullary fixation assembly includes a proximal
screw member positioned at a proximal end of the intramedullary
fixation assembly, a distal member positioned at a distal end of
the intramedullary fixation assembly, where the proximal screw
member is slideably coupled to the distal member and makes a fixed
angle with the distal member.
Inventors: |
Tyber; Jeff; (Bethlehem,
PA) ; Gannoe; Jamy; (West Milford, NJ) ;
Digiovanni; Chris; (Barrington, RI) |
Correspondence
Address: |
WARD & OLIVO
SUITE 300, 382 SPRINGFIELD AVENUE
SUMMIT
NJ
07901
US
|
Family ID: |
42165904 |
Appl. No.: |
12/456808 |
Filed: |
June 23, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61132932 |
Jun 24, 2008 |
|
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|
Current U.S.
Class: |
606/62 |
Current CPC
Class: |
A61B 17/683 20130101;
A61F 2002/4238 20130101; A61B 17/8625 20130101; A61B 17/1717
20130101; A61B 17/864 20130101; A61B 17/1775 20161101; A61B 17/72
20130101; A61B 17/8605 20130101; A61B 17/88 20130101 |
Class at
Publication: |
606/62 |
International
Class: |
A61B 17/56 20060101
A61B017/56 |
Claims
1. An intramedullary fixation assembly for bone fusion, comprising:
a proximal screw member positioned at a proximal end of the
intramedullary fixation assembly; and a distal member positioned at
a distal end of the intramedullary fixation assembly, wherein the
proximal screw member is slideably coupled to the distal member and
makes a fixed angle with the distal member.
2. The intramedullary fixation assembly of claim 1, wherein the
proximal screw member comprises a first elongated body, wherein the
first elongated body includes a first threaded portion at a first
end and a bulbous portion at a second end.
3. The intramedullary fixation assembly of claim 2, wherein the
bulbous portion includes a taper for providing an interference fit
with the distal member.
4. The intramedullary fixation assembly of claim 3, wherein the
taper provides for an interference lock with the distal member.
5. The intramedullary fixation assembly of claim 4, wherein the
proximal screw member is cannulated having a circular cross-section
with the first elongated body.
6. The intramedullary fixation assembly of claim 5, wherein the
bulbous portion further includes an orifice longitudinally
coextensive with a length of the bulbous portion.
7. The intramedullary fixation assembly of claim 6, wherein the
orifice has a hexagonal shape, a star shape, or a square shape.
8. The intramedullary fixation assembly of claim 7, wherein the
orifice is provided to receive a complementary shaped end of an
instrument.
9. The intramedullary fixation assembly of claim 8, wherein the
first threaded portion contains a plurality of bone threads on an
outer surface of the threaded portion.
10. The intramedullary fixation assembly of claim 9, wherein the
first threaded portion includes a self-tapping edge, wherein the
self-tapping edge provides for removal of bone material during
insertion of the proximal screw member.
11. The intramedullary fixation assembly of claim 10, wherein the
distal member further includes a second elongated body, wherein the
second elongated body contains a second threaded portion at a third
end, and an opening at a fourth end.
12. The intramedullary fixation assembly of claim 11, wherein the
distal member further includes a plurality of first and second
grooves for coupling to an instrument, wherein the plurality of
first and second grooves are disposed at the opening at the fourth
end.
13. The intramedullary fixation assembly of claim 12, wherein the
distal member further comprises a plurality of apertures disposed
in the second elongated body.
14. The intramedullary fixation assembly of claim 13, wherein the
plurality of apertures includes a first internal aperture and a
tapered internal aperture.
15. The intramedullary fixation assembly of claim 14, wherein the
first internal aperture longitudinally traverses the second
elongated body from the third end to the fourth end.
16. The intramedullary fixation assembly of claim 15, wherein the
first internal aperture further includes a hexagonally shaped
opening, a star-shaped opening, or a square-shaped opening
partially disposed in the second elongated body.
17. The intramedullary fixation assembly of claim 16, wherein the
opening is provided to receive a complementary shaped member.
18. The intramedullary fixation assembly of claim 17, wherein the
internal tapered aperture traverses the second elongated body from
the fourth end to an exterior surface on the second elongated
body.
19. The intramedullary fixation assembly of claim 18, wherein the
first internal aperture is provided to receive the first elongated
body of the proximal screw member, wherein the bulbous portion is
contained in the first internal aperture, and further wherein the
bulbous portion abuts the opening at the fourth end.
20. The intramedullary fixation assembly of claim 19, wherein the
first threaded portion is at an opposite end to the second threaded
portion in the intramedullary fixation assembly.
21. The intramedullary fixation assembly of claim 20, wherein the
internal tapered aperture forms a predetermined angle with the
first internal aperture.
22. The intramedullary fixation assembly of claim 21, wherein the
predetermined angle determines the angle for arch restoration.
23. The intramedullary fixation assembly of claim 22, wherein the
second threaded portion contains a plurality of threads on an outer
surface of the second threaded portion.
24. The intramedullary fixation assembly of claim 23, wherein the
second threaded portion includes a self-tapping edge, `wherein the
self-tapping edge provides for removal of bone material during
insertion of the distal screw member.
25. The intramedullary fixation assembly of claim 24, wherein the
proximal screw member is provided for insertion into a first
medullary canal of a first bone.
26. The intramedullary fixation assembly of claim 25, wherein the
distal member is provided for insertion into a second medullary
canal of a second bone.
27. The intramedullary fixation assembly of claim 26, wherein the
predetermined angle is between 0 to 180 degrees.
28. A method for bone fusion, comprising: providing an
intramedullary fixation assembly, wherein the intramedullary
fixation assembly further comprises: a proximal screw member
positioned at a proximal end of the intramedullary fixation
assembly; and a distal member positioned at a distal end of the
intramedullary fixation assembly, wherein the proximal screw member
is slideably coupled to the distal member and makes a fixed angle
with the distal member; drilling a first medullary canal in a first
bone and drilling a second medullary canal in a second bone;
inserting the distal member into the first medullary canal;
coupling the instrument to the distal member; slideably coupling
the proximal screw member to the distal member; inserting the
proximal screw member into the second medullary canal; applying
compression to the proximal screw member to lock the distal member
to the proximal screw member, thereby fusing the first bone to the
second bone.
29. The method of claim 28, wherein the proximal screw member
comprises a first elongated body, wherein the first elongated body
includes a first threaded portion at a first end and a bulbous
portion at a second end.
30. The method of claim 29, wherein the bulbous portion includes a
locking mechanism for providing an interference fit with the distal
member.
31. The method of claim 30, wherein the locking mechanism provides
for an interference lock with the distal member.
32. The method of claim 31, wherein the locking mechanism includes
a morse taper for providing an interference lock with the distal
member.
33. The method of claim 32, wherein the proximal screw member is
cannulated having a circular cross-section with the first elongated
body.
34. The method of claim 33, wherein the bulbous portion further
includes an orifice longitudinally coextensive with a length of the
bulbous portion.
35. The method of claim 34, wherein the orifice has a hexagonal
shape, a star shape, or a square shape.
36. The method of claim 35, wherein the orifice is provided to
receive a complementary shaped end of an instrument.
37. The method of claim 36, wherein the first threaded portion
contains a plurality of bone threads on an outer surface of the
threaded portion.
38. The method of claim 37, wherein the first threaded portion
includes a self-tapping edge, wherein the self-tapping edge
provides for removal of bone material during insertion of the
proximal screw member.
39. The method of claim 38, wherein the distal member further
includes a second elongated body, wherein the second elongated body
contains a second threaded portion at a third end, and an opening
at a fourth end.
40. The method of claim 39, wherein the distal member further
includes a plurality of first and second grooves for coupling to
the instrument, wherein the plurality of first and second grooves
are disposed at the opening at the fourth end.
41. The method of claim 40, wherein the distal member further
comprises a plurality of apertures disposed in the second elongated
body.
42. The method of claim 41, wherein the plurality of apertures
includes a first internal aperture and a tapered internal
aperture.
43. The method of claim 42, wherein the first internal aperture
longitudinally traverses the second elongated body from the third
end to the fourth end.
44. The method of claim 43, wherein the first internal aperture
further includes a hexagonally shaped opening, a star-shaped
opening, or a square-shaped opening partially disposed in the
second elongated body.
45. The method of claim 44, wherein the opening is provided to
receive a complementary shaped member.
46. The method of claim 45, wherein the internal tapered aperture
traverses the second elongated body from the fourth end to an
exterior surface on the second elongated body.
47. The method of claim 46, wherein the first internal aperture is
provided to receive the first elongated body of the proximal screw
member, wherein the bulbous portion is contained in the first
internal aperture, and further wherein the bulbous portion abuts
the opening at the fourth end.
48. The method of claim 47, wherein the first threaded portion is
at an opposite end to the second threaded portion in the
intramedullary fixation assembly.
49. The method of claim 48, wherein the internal tapered aperture
forms a predetermined angle with the first internal aperture.
50. The method of claim 49, wherein the predetermined angle
determines the angle for arch restoration.
51. The method of claim 50, wherein the predetermined angle is
between 0 and 180 degrees.
52. The method of claim 51, wherein the second threaded portion
contains a plurality of threads on an outer surface of the second
threaded portion.
53. The method of claim 52, wherein the second threaded portion
includes a self-tapping edge, wherein the self-tapping edge
provides for removal of bone material during insertion of the
distal screw member.
54. The method of claim 53, wherein the first medullary canal is
located in a metatarsal bone in the human foot.
55. The Method of claim 54, wherein the second medullary canal is
located in a cuneiform bone, a navicular bone, or a talus bone in
the human foot.
56. A fixation system, comprising: a proximal screw member
positioned at a proximal end of the intramedullary fixation
assembly; a distal member positioned at a distal end of the
intramedullary fixation assembly, wherein the proximal screw member
is slideably coupled to the distal member and makes a fixed angle
with the distal member.
57. The fixation system of claim 56, wherein the proximal screw
member comprises a first elongated body, wherein the first
elongated body includes a first threaded portion at a first end and
a bulbous portion at a second end.
58. The fixation system of claim 57, wherein the bulbous portion
includes a locking mechanism for providing an interference fit with
the distal member.
59. The fixation system of claim 58, wherein the locking mechanism
provides for an interference lock with the distal member.
60. The fixation system of claim 59, wherein the locking mechanism
includes a morse taper for providing an interference lock with the
distal member.
61. The fixation system of claim 60, wherein the proximal screw
member is cannulated having a circular cross-section with the first
elongated body.
62. The fixation system of claim 61, wherein the bulbous portion
further includes an orifice longitudinally coextensive with a
length of the bulbous portion.
63. The fixation system of claim 62, wherein the orifice has a
hexagonal shape, a star shape, or a square shape.
64. The fixation system of claim 63, wherein the orifice is
provided to receive a complementary shaped end of a member.
65. The fixation system of claim 63, wherein the first threaded
portion contains a plurality of bone threads on an outer surface of
the threaded portion.
66. The fixation system of claim 65, wherein the first threaded
portion includes a self-tapping edge, wherein the self-tapping edge
provides for removal of bone material during insertion of the
proximal screw member.
67. The fixation system of claim 66, wherein the distal member
further includes a second elongated body, wherein the second
elongated body contains a second threaded portion at a third end,
and an opening at a fourth end.
68. The fixation system of claim 67, wherein the distal member
further includes a plurality of first and second grooves, wherein
the plurality of first and second grooves are disposed at the
opening at the fourth end.
69. The fixation system of claim 68, wherein the distal member
further comprises a plurality of apertures disposed in the second
elongated body.
70. The fixation system of claim 69, wherein the plurality of
apertures includes a first internal aperture and a tapered internal
aperture.
71. The fixation system of claim 70, wherein the first internal
aperture longitudinally traverses the second elongated body from
the third end to the fourth end.
72. The fixation system of claim 71, wherein the first internal
aperture further includes a hexagonally shaped opening, a
star-shaped opening, or a square-shaped opening partially disposed
in the second elongated body.
73. The fixation system of claim 72, wherein the opening is
provided to receive a complementary shaped member.
74. The fixation system of claim 73, wherein the internal tapered
aperture traverses the second elongated body from the fourth end to
an exterior surface on the second elongated body.
75. The fixation system of claim 74, wherein the first internal
aperture is provided to receive the first elongated body of the
proximal screw member, wherein the bulbous portion is contained in
the first internal aperture, and further wherein the bulbous
portion abuts the opening at the fourth end.
76. The fixation system of claim 75, wherein the first threaded
portion is at an opposite end to the second threaded portion in the
intramedullary fixation assembly.
77. The fixation system of claim 76, wherein the internal tapered
aperture forms a predetermined angle with the first internal
aperture.
78. The fixation system of claim 77, wherein the predetermined
angle determines the angle for arch restoration.
79. The fixation system of claim 78, wherein the predetermined
angle is between 0 and 180 degrees.
80. The fixation system of claim 79, wherein the second threaded
portion contains a plurality of threads on an outer surface of the
second threaded portion.
81. The fixation system of claim 80, wherein the second threaded
portion includes a self-tapping edge, wherein the self-tapping edge
provides for removal of bone material during insertion of the
distal screw member.
82. The fixation system of claim 81, wherein the proximal screw
member is provided for insertion into a first medullary -canal of a
first bone.
83. The fixation system of claim 82, wherein the distal member is
provided for insertion into a second medullary canal of a second
bone.
84. The fixation system of claim 83, wherein the first medullary
canal is located in a cuneiform bone, a navicular bone, or a talus
bone in the human foot.
85. The fixation system of claim 84, wherein the second medullary
canal is located in a metatarsal bone in the human foot.
86. An intramedullary fixation, assembly for metatarsal bone fusion
in a human foot, comprising: a proximal screw member for coupling
to a cuneiform bone, a navicular bone, or a talus bone, wherein the
proximal screw member is positioned at a proximal end of the
intramedullary fixation assembly; and a distal member for
connecting to a metatarsal bone, wherein the distal member is
positioned at a distal end of the intramedullary fixation assembly,
wherein the proximal screw member is slideably coupled to the
distal member and makes a fixed angle with the distal member.
87. The intramedullary fixation assembly of claim 86, wherein the
proximal screw member comprises a first elongated body, wherein the
first elongated body includes a first threaded portion at a first
end and a bulbous portion at a second end.
88. The intramedullary fixation assembly of claim 87, wherein the
bulbous portion includes a locking mechanism for providing an
interference fit with the distal member.
89. The intramedullary fixation assembly of claim 88, wherein the
locking mechanism provides for an interference lock with the distal
member.
90. The intramedullary fixation assembly of claim 89, wherein the
locking mechanism includes a morse taper.
91. The intramedullary fixation assembly of claim 90, wherein the
proximal screw member is cannulated having a circular cross-section
with the first elongated body.
92. The intramedullary fixation assembly of claim 91, wherein the
bulbous portion further includes an orifice longitudinally
coextensive with a length of the bulbous portion.
93. The intramedullary fixation assembly of claim 92, wherein the
orifice has a hexagonal shape, a star shape, or a square shape.
94. The intramedullary fixation assembly of claim 93, wherein the
orifice is provided to receive a complementary shaped end of a
member.
95. The intramedullary fixation assembly of claim 93, wherein the
first threaded portion contains a plurality of bone threads on an
outer surface of the threaded portion.
96. The intramedullary fixation assembly of claim 95, wherein the
first threaded portion includes a self-tapping edge, wherein the
self-tapping edge provides for removal of bone material during
insertion of the proximal screw member.
97. The intramedullary fixation assembly of claim 96, wherein the
distal member further includes a second elongated body, wherein the
second elongated body contains a second threaded portion at a third
end, and an opening at a fourth end.
98. The intramedullary fixation assembly of claim 97, wherein the
distal member further includes a plurality of first and second
grooves for coupling to an instrument, wherein the plurality of
first and second grooves are disposed at the opening at the fourth
end.
99. The intramedullary fixation assembly of claim 98, wherein the
distal member further comprises a plurality of apertures disposed
in the second elongated body.
100. The intramedullary fixation assembly of claim 99, wherein the
plurality of apertures includes a first internal aperture and a
tapered internal aperture.
101. The intramedullary fixation assembly of claim 100, wherein the
first internal aperture longitudinally traverses the second
elongated body from the third end to the fourth end.
102. The intramedullary fixation assembly of claim 101, wherein the
first internal aperture further includes a hexagonally shaped
opening, a star-shaped opening, or a square-shaped opening
partially disposed in the second elongated body.
103. The intramedullary fixation assembly of claim 102, wherein the
opening is provided to receive a complementary shaped member.
104. The intramedullary fixation assembly of claim 103 wherein the
internal tapered aperture traverses the second elongated body from
the fourth end to an exterior surface on the second elongated
body.
105. The intramedullary fixation assembly of claim 104, wherein the
first internal aperture is provided to receive the first elongated
body of the proximal screw member, wherein the bulbous portion is
contained in the first internal aperture, and further wherein the
bulbous portion abuts the opening at the fourth end.
106. The intramedullary fixation assembly of claim 105, wherein the
first threaded portion is at an opposite end to the second threaded
portion in the intramedullary fixation assembly.
107. The intramedullary fixation assembly of claim 106, wherein the
internal tapered aperture forms a predetermined angle with the
first internal aperture.
108. The intramedullary fixation assembly of claim 107, wherein the
predetermined angle determines the angle for arch restoration.
109. The intramedullary fixation assembly of claim 108, wherein the
predetermined angle is between 0 and 180 degrees.
110. The intramedullary fixation assembly of claim 109, wherein the
second threaded portion contains a plurality of threads on an outer
surface of the second threaded portion.
111. The intramedullary fixation assembly of claim 110, wherein the
second threaded portion includes a self-tapping edge, wherein the
self-tapping edge provides for removal of bone material during
insertion of the distal screw member.
112. The intramedullary fixation assembly of claim 111, wherein the
proximal screw member is provided for insertion into a first
medullary canal of a cuneiform bone, a navicular bone, or a talus
bone.
113. The intramedullary fixation assembly of claim 112, wherein the
distal member is provided for insertion into a second medullary
canal of a metatarsal bone.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Provisional
Application No. 61/132,932, filed Jun. 24, 2008, the entire
contents of which are herein incorporated by reference.
FIELD OF THE INVENTION
[0002] This invention relates to the field of orthopedic implant
devices, and more particularly, to an intramedullary fixation
assembly used for internal fixation of angled joints, bones and
deformity correction, such as the bones in the foot.
BACKGROUND OF THE INVENTION
[0003] Orthopedic implant devices, such as intramedullary nails,
plates, rods and screws are often used to repair or reconstruct
bones and joints affected by trauma, degeneration, deformity and
disease, such as Charcot arthropathy caused by diabetes in some
patients. Charcot arthropathy (or Charcot foot) is a destructive
process affecting many regions including joints of the foot and
ankle in diabetics. This condition causes bony fragmentation,
dislocation, and fractures that eventually progresses to foot
deformity, bony prominences, ulceration and instability of the
foot. Charcot arthropathy can affect any joint in the body but is
often seen in the feet affecting the metatarsal, tarsometatarsal
and tarsal joints and frequently causes the foot to lose its arch
or curvature, thus resulting in "flat footedness" in the mid-foot
region.
[0004] Early treatment for Charcot foot includes the use of
therapeutic footwear, immobilization of the foot and/or non-weight
bearing treatment. Surgical treatments include orthopedic fixation
devices that fixate the bones in order to fuse them into a stable
mass. These orthopedic implant devices realign bone segments and
hold them together in compression until healing occurs, resulting
in a stable mass.
[0005] Various implants have been utilized for surgical treatment,
including bone screws. While these devices allow fixation and
promote fusion, they do not deliver restoration of the arch in
a
[0006] Charcot foot. Instead, the physician must estimate the arch
and manually align the bones and deliver the screws to hold the
bones in place, while reducing bone purchase. Intramedullary nails
and/or a plate with a lag screw too have deficiencies. These
intramedullary nails also do not reconstruct an arch that is lost
due to Charcot foot disease.
[0007] Moreover, infections and wound complications are a major
concern in aforementioned procedures. Wound closure is technically
demanding for the surgeon, and devices that add surface prominence,
such as plates or exposed screws, add to the difficulty by
requiring greater tissue tension during incision reapproximation.
This increases the risk of postoperative wound infections and
dehiscence that may ultimately result in limb amputation.
[0008] There is therefore a need for an intramedullary fixation
assembly and method of use that overcomes some or all of the
previously delineated drawbacks of prior fixation assemblies.
SUMMARY OF THE INVENTION
[0009] An object of the present invention is to overcome the
drawbacks of previous inventions.
[0010] Another object of the present invention is to provide a
novel and useful intramedullary fixation assembly that may be
utilized to treat any bones in human body.
[0011] Another object of the present invention is to provide a
novel and useful intramedullary fixation assembly that may be
utilized to treat bones in a mid-foot region.
[0012] Another object of the present invention is to restore the
arch by utilizing an intramedullary assembly.
[0013] Another object of the present invention is to provide a
system for treating deteriorating bones in a mid-foot region.
[0014] Another object of the present invention is to provide a
method for restoring the arch of the foot by delivering a fixator
that can be coupled in a patient's foot.
[0015] In a first non-limiting aspect of the present invention, a
fixation assembly comprising two members is provided. A first
member, positioned at a proximal end of the fixation assembly, has
an elongated portion and a tapered bulbous end. A second member,
positioned at a distal end of the fixation assembly, has an
internal tapered aperture, wherein the elongated portion resides
within the internal tapered aperture. The first member forms a
fixed angle with the second member, thereby selectively coupling
the first member to the second member.
[0016] In a second non-limiting aspect of the present invention, a
method for reconstructing an arch in a mid-foot region comprises
eight steps. Step one includes making an incision in the mid-foot
region of a patient's foot. Step two includes gunstocking the foot
to expose the articular surface. Step three includes reaming the
intramedullary canal and inserting a distal member. Step four
includes coupling the instrument to the distal member. Step five
includes assessing the position of the proximal member with a guide
wire. Step six includes pre-drilling a hole through the joints
selected for fusion. The seventh step includes inserting the
proximal member over the guide wire until rigid connection with the
tapered aperture is made that compresses the joint and wherein the
proximal member is at an angle to the distal member. The eighth
step includes removing the instrument and closing the incision,
thereby causing the arch to be formed in the mid-foot region.
[0017] In a third non-limiting aspect of the present invention, an
instrument is combined with a fixation assembly for reconstructing
an arch in a mid-foot region. The instrument has a handle, a
"U-shaped" recess having two sides and a tapered bore. The
intramedullary fixation assembly has a first member and a second
member. The first member is positioned at a proximal end of the
intramedullary fixation assembly. The first member has an elongated
portion and a bulbous portion. The second member is positioned at a
distal end of the intramedullary fixation assembly. The second
member has an internal tapered aperture, a plurality of grooves and
a threaded portion. The elongated portion resides within the
internal tapered aperture, and a "U-shaped" recess having two sides
that couple the first member to the second member, and further
coupling the instrument to the intramedullary fixation assembly for
reconstructing the arch in the mid-foot region.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] A further understanding of the present invention can be
obtained by reference to a preferred embodiment set forth in the
illustrations of the accompanying drawings. Although the
illustrated embodiment is merely exemplary of systems and methods
for carrying out the present invention, both the organization and
method of operation of the invention, in general, together with
further objectives and advantages thereof, may be more easily
understood by reference to the drawings and the following
description. The drawings are not intended to limit the scope of
this invention, which is set forth with particularity in the claims
as appended or as subsequently amended, but merely to clarify and
exemplify the invention.
[0019] For a more complete understanding of the present invention,
reference is now made to the following drawings in which:
[0020] FIG. 1 is a perspective view of a fixation system according
to a preferred embodiment of the present invention.
[0021] FIG. 2 is a perspective view of a proximal screw member used
in the fixation system shown in FIG. 1 according to the preferred
embodiment of the present invention.
[0022] FIG. 3A is a perspective view of a distal member used in the
fixation system shown in FIG. 1 according to the preferred
embodiment of the present invention.
[0023] FIG. 3B is a perspective cross-sectional view of the distal
member shown in FIG. 3A according to the preferred embodiment of
the invention.
[0024] FIG. 4 is a perspective view of the instrument member used
in the fixation system shown in FIG. 1 according to the preferred
embodiment of the present invention.
[0025] FIG. 5 is a perspective view of the assembled intramedullary
fixation assembly inserted into the bones of a patient's foot
according to the preferred embodiment of the present invention.
[0026] FIG. 6 is a side view of the assembled intramedullary
fixation assembly shown in FIG. 5 according to the preferred
embodiment of the present invention.
[0027] FIG. 7 is a flow chart illustrating the method of coupling
the intramedullary fixation assembly shown in FIGS. 1-6 to tarsal
and metatarsal bones in a patient's foot according to the preferred
embodiment of the present invention.
DETAILED DESCRIPTION
[0028] The present invention may be understood more readily by
reference to the following detailed description of preferred
embodiment of the invention. However, techniques, systems and
operating structures in accordance with the present invention may
be embodied in a wide variety of forms and modes, some of which may
be quite different from those in the disclosed embodiment.
Consequently, the specific structural and functional details
disclosed herein are merely representative, yet in that regard,
they are deemed to afford the best embodiment for purposes of
disclosure and to provide a basis for the claims herein, which
define the scope of the present invention. It must be noted that,
as used in the specification and the appended claims, the singular
forms "a", "an", and "the" include plural referents unless the
context clearly indicates otherwise.
[0029] Referring now to FIG. 1, there is shown a fixation system
100 which is made in accordance with the teachings of the preferred
embodiment of the invention. As shown, the fixation system 100
includes an intramedullary fixation assembly 110, comprising a
proximal `screw member 130 and a distal member 140. Proximal screw
member 130 is provided on proximal end 135 of assembly 110 and is
coupled to a distal member 140 that is provided on the distal end
145 of the fixation assembly 110. Also, proximal screw member 130
makes a fixed angle 150 with distal member 140 and this angle 150
determines the angle for arch restoration. Moreover, fixation
system 100 includes instrument 120 that is utilized to couple
intramedullary fixation assembly 110 to the bones, in one
non-limiting example, in the mid-foot region (not shown). It should
be appreciated that in one non-limiting embodiment, intramedullary
fixation assembly 110 may be made from a Titanium material,
although, in other non-limiting embodiments, intramedullary
fixation assembly 110 may be made from SST; PEEK, NiTi, Cobalt
chrome or other similar types of materials. It should also be
appreciated that intramedullary fixation assembly 110 may be
utilized for the internal fixation of other bones in the human
body.
[0030] As shown in FIG. 2, proximal screw member 130 is generally
cylindrical in shape and extends from first bulbous portion 202 to
second tapered end 204. End 204 has a diameter that is slightly
smaller than diameter 226 of bulbous portion 202. Additionally,
bulbous portion 202 has a taper, such as a Morse taper, with a
width that decreases from end 211 to end 212. The taper allows for
a locked interference fit with tapered aperture 316 when tapered
bulbous portion 202 is combined with tapered aperture 316, shown
and described below. Moreover, bulbous portion 202 is generally
circular and has a generally hexagonal torque transmitting aperture
208 that traverses length 210 of bulbous portion 202. However, a
star-shaped aperture, a square-shaped aperture, or any other shaped
aperture may be utilized without departing from the scope of the
present invention. Torque transmitting aperture 208 is utilized to
transmit a torque from bulbous portion 202 to tapered end 204 by
rotating bulbous portion 202.
[0031] Further, proximal screw member 130 has a first smooth
exterior portion 206 extending from end 212 of bulbous portion 202.
Portion 206 comprises an internal aperture 214 that longitudinally
traverses portion 206 in direction 201. Portion 206 terminates into
a second generally tubular portion 216. Portion 216 may comprise
internal circular aperture 220 that longitudinally traverses inside
portion 216. Internal circular aperture 220 is aligned with
apertures 214 and 208 along axis 203 to form a continuous opening
(i.e., a cannula) from bulbous portion 202 to end 204. The
continuous opening or cannula is provided to interact with a guide
wire (not shown) by receiving the guide wire within the continuous
opening thereby positioning and locating the proximal member 130.
In other non-limiting embodiments, the proximal member 130 may be
provided without apertures 220 and 214 (i.e., the proximal member
is solid).
[0032] Furthermore, tubular portion 216 has a plurality of circular
threads, such as threads 218, which are circumferentially disposed
on the external surface of portion 216 and, with threads 218 having
an external diameter 224. Portion 216 may also be provided with a
self-tapping leading edge 222 to provide portion 216 with the
ability to remove bone material during insertion of proximal screw
member 130 into bone. It should be appreciated that the length of
the proximal member 130 may be selected of varying lengths to allow
a surgeon to fuse different joints in a foot (not shown).
[0033] As shown in FIGS. 3A-3B, distal member 140 of the preferred
embodiment is generally tubular in shape and tapers from a first
end 302 to a second end 304 (i.e. end 302 has a diameter 306 that
is slightly larger than diameter 308 of end 304). However, in
another non-limiting embodiment, distal. member 140 has a constant
width from first end 302 to second end 304. Further, first end 302
is generally semi-spherical in shape and has an internal circular
aperture 316, which traverses end 302 along direction 301 (i.e. end
302 is generally "donut" shaped). Additionally, circular aperture
316 emanates from surface 322, such that portion 310 has a
generally tapered aperture 316 provided in portion 310. Circular
aperture 316 comprises slope 320 from first end 302 to end 322 of
portion 310. Further, aperture 316 is aligned along axis 303, which
is offset from horizontal axis 305 of distal member 140. Axis 303
forms an angle 150 with horizontal axis 305 that determines the
angle for arch restoration, as shown in FIG. 3A. Angle 150 may be
any angle greater than 90 degrees and less than 180 degrees.
Tapered aperture 316 when combined with tapered bulbous portion
202, shown in FIG. 2, creates a locked interference fit between
proximal member 130 and distal member 140. First end 302 has a
plurality of substantially similar grooves 326 and 328, which form
an "L-shape" with surface 330 of end 302. Grooves 326 and 328 are
provided to receive instrument 120 of fixation system 100, which is
later described. In other non-limiting embodiments, other similar
instruments may be provided to be received within grooves 326 and
328.
[0034] Distal member 140 further comprises a generally smooth
portion 310 coupled to end 302. Portion 310 has a generally
hexagonal shaped aperture 312, which opens into aperture 316 and
which longitudinally traverses through portion 310 in direction
301. In other non-limiting embodiments, a star-shaped aperture, a
square-shaped aperture, or any other shaped aperture may be
utilized. Circular aperture 316 has a diameter 314 that is slightly
larger than external diameter 224 of portion 216 and 206 of
proximal screw member 130, with portions 216 and 206 being slidably
received within aperture 316 of portion 310. Aperture 316 has a
diameter that is smaller than diameter 226 of bulbous -portion
202.
[0035] Portion 310 of distal member 140 terminates into a second
generally cylindrical portion 318 which has a plurality of threads
324, which are circumferentially disposed on the external surface
of portion 318. Portion 318 has an internal circular aperture 326
which is longitudinally coextensive with portion 318 in direction
301. Circular aperture 326 aligns with aperture 312 to form a
continuous opening from end 302 to end 304.
[0036] As shown in FIG. 4, instrument 120 is illustrated for
coupling proximal screw member 130 to distal member 140.
Particularly, instrument 120 includes a handle portion 402 coupled
to a rod portion 404. Rod portion 404 emanates from handle portion
402 at end 406 and terminates into a rectangular planar portion 408
at end 410. Planar portion 408 is aligned along axis 401 and is
fixably coupled to a generally cylindrical tubular portion 412
(i.e., an aiming device). Portion 412 traverses portion 408 from
top surface 414 to bottom surface 416. Further, tubular portion 412
is aligned along dissimilar axis 403, forming an angle 405 with
axis 401. Also, tubular portion 412 has a through aperture 420 that
longitudinally traverses portion 412 along axis 403.
[0037] Planar portion 408 is coupled to planar portion 422, with
portion 422 having a width slightly smaller than width of portion
408. Portion 422 terminates into a generally "U-shaped" portion 424
with portion 424 being orthogonal to portion 422. Further, portion
424 has a plurality of substantially similar sides 426 and 428
which are provided to be slidably coupled to grooves 326 and 328 of
distal member 140.
[0038] In operation, sides 426 and 428 of instrument 120 are
received in respective grooves 326 and 328 of distal member 140, of
FIGS. 3A-3B, thereby slidably coupling distal member 140 to
instrument 120. In this position, axis 303 of aperture 316 is
aligned along substantially the same axis as axis 403 of instrument
120. Proximal screw member 130 is coupled to distal member 140 by
slidably coupling portions 206 and 216 through aperture 420 of
tubular portion 412. Tubular portion 412 guides proximal screw
member 130 through internal aperture 420 and into aperture 316 on
surface 322 and may also guide a Kirschner wire (K wire) or a
drill. Proximal screw member 130, of FIG. 2, travels into bone as
portions 216 and 206 travel further through aperture 316 at end 302
until bulbous portion 202 is restrained by surface 322 and end 302.
Aperture 316, being tapered along axis 303, causes proximal screw
member 130 to form an angle 150 with distal member 140, with
proximal member 130 being aligned along an axis 303, which is
substantially the same axis as axis 403 of tubular portion 412 of
instrument 120.
[0039] In operation, and as best shown in FIGS. 5, 6 and 7, the
fixation system 100 utilizes the intramedullary fixation assembly
110 for treating and fixating the deteriorated and damaged or
fractured bones in the human foot 500. This restores the arch in a
human foot 500 by coupling the intramedullary fixation assembly 110
to the human foot 500 of a left leg. In one-non limiting example,
and as shown in FIG. 5, the intramedullary assembly 110 is coupled
to the medullary canals of the first metatarsal 502, medial
cuneiform 504, navicular 506 and talus bone 508. Talus bone 508
makes up part of the ankle joint where the threaded portion 216 of
the proximal screw member 130 of the intramedullary assembly 110 is
threadably coupled. The medial cuneiform 504 and navicular 506
bones are most affected by Diabetic Charcot foot disorder that
causes deterioration and collapse of the arch of the foot 500. It
should be appreciated that the intramedullary assembly 110 may be
used within each of the five rays, with a ray representing a line
drawn from each metatarsal bone to the talus. The angulation in the
smaller rays will be smaller than the two rays (i.e., a line from
the first and second metatarsal bones to the talus bone). Also, the
diameter of distal member 140 will decrease from the large ray to
the small ray. In one non-limiting example, the angulation may be
any angle greater than 90 degrees and less than 180 degrees. For
example, the angle for the first ray may be 150-170 degrees and the
angles for the other rays may be 160-175 degrees.
[0040] As shown in FIGS. 6 and 7, the intramedullary fixation
assembly 110 may be utilized to reconstruct an arch in a mid-foot
region of a human foot 500. As shown, the method starts in step 700
and proceeds to step 702, whereby a Dorsal Lis Franc incision
(i.e., mid-foot incision) (not shown) is made in foot 500 in order
to gain access to the joint. In step 704, the joint capsule is
separated by "Gunstocking" foot 500 in direction 601 (i.e., the
foot 500 is bent mid-foot) to expose the articular surface 602 and
the articulating cartilage is removed. Next, in step 706, the
intramedullary canal is reamed and the distal member 140 is
inserted into the intramedullary canal (not shown) of the
metatarsal 502. In other non-limiting embodiments, the distal
member 140 may be inserted by impaction, by press fit, by reaming a
hole in the intramedullary canal (not shown) or substantially any
other similar strategy or technique. Next, in step 708, the
instrument 120 is coupled to the distal member 140 by coupling
sides 426 and 428 of instrument 120 to respective grooves 326 and
328. In step 710, initial positioning of the proximal member 130 is
assessed with the use of a guide wire through portion 412 (i.e.,
aiming device). Next, in step 712, a countersink drill is inserted
through portion 412 and the proximal cortex is penetrated. In this
step, a cannulated drill or guide wire is used to pre-drill the
hole through the joints selected for fusion. In step 714, the
proximal screw member 130 is inserted over the guide wire and into
the distal member 140. Particularly, the proximal member 130 is
inserted through tubular portion 412 (i.e., aiming device), causing
proximal member 130 to travel through internal longitudinal
aperture 420, into distal member 140 and further into bones 504,
506 and 508 until rigid connection with the tapered aperture 316 is
made, thereby compressing the joint. In one non-limiting
embodiment, a locking element (not shown) such as a plate or a
washer is coupled to end 302 of the intramedullary fixation
assembly 110 to further secure proximal threaded member 130 to
distal member 140. Next, in step 716 the instrument 120 is removed
and the dorsal Lis Franc (i.e., mid-foot) incision is closed. The
method ends in step 718.
[0041] It should be appreciated that a plurality of intramedullary
fixation assemblies, such as intramedullary fixation assembly 110,
may be inserted into any of the bones of a foot 500 such as, but
not limited to the metatarsal, cuneiform, calcaneus, cuboid, talus
and navicular bones, in order to restore the natural anatomical
shape of the arch of the foot 500. Thus, the fixation system 100,
in one non-limiting embodiment, is utilized to couple the
intramedullary fixation assembly 110 to the foot 500, which causes
the metatarsal 504, medial cuneiform 504, navicular 506 and talus
508 bones to be aligned to the proper anatomical shape of an arch
when assembled within foot 500. It should be appreciated that the
intramedullary fixation assembly 110 is delivered through a dorsal
midfoot incision, thereby reducing the disruption to the plantar
tissues and/or the metatarsal heads while at the same time
minimizing the tension on the skin. This allows for improved wound
closure, reduced operating room time, reduction in the number of
incisions required and reduction in the total length of incisions.
It should also be appreciated that in other non-limiting
embodiments, the intramedullary assembly 110 may be utilized with
graft material (i.e., autograft, allograft or other biologic
agent).
[0042] It should be understood that this invention is not limited
to the disclosed features and other similar method and system may
be utilized without departing from the spirit and the scope of the
present invention.
[0043] While the present invention has been described with
reference to the preferred embodiment and alternative embodiments,
which embodiments have been set forth in considerable detail for
the purposes of making a complete disclosure of the invention, such
embodiments are merely exemplary and are not intended to be
limiting or represent an exhaustive enumeration of all aspects of
the invention. The scope of the invention, therefore, shall be
defined solely by the following claims. Further, it will be
apparent to those of skill in the art that numerous changes may be
made in such details without departing from the spirit and the
principles of the invention. It should be appreciated that the
present invention is capable of being embodied in other forms
without departing from its essential characteristics.
* * * * *